Method and device for controlling information signal recording

ABSTRACT

An anti-duplication control signal detection section detects an anti-duplication control signal added on a video signal S 1  and supplies it to a system controller as a duplication prevention control information S 2.  A write control section of the system controller stops the duplication of the video signal in a disk if the anti-duplication control information is an information which indicates duplication inhibition. In this case, the video signal recorded in the disk is erased under the control from the erasing control section by the time the duplication prevention control corresponding to the anti-duplication control signal becomes active.

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] This invention relates to a method and device for controllingduplication prevention of an information signal using, for example, ananti-duplication control signal recorded in a recording medium togetherwith the information signal.

[0003] 2. Description of Related Art

[0004] VTR (Video Tape Recorder) has been popularized and a lot ofsoftware for being played back on a VTR is available. Recently playbackdevices and recording/playback devices such as a digital VTR and DVD(Digital Video Disk) have been used practically, and pictures and soundof good quality can be played back and viewed easily.

[0005] However, on the other hand, the popularization gives rise to aproblem that such abundant software is duplicated without anyrestriction, and heretofore various duplication prevention measures areavailable.

[0006] For example, though it is not a method for directly inhibitingduplication of analog video signals, a method has been available inwhich the difference in AGC (Auto Gain Control) system or APC (AutoPhase Control) characteristics between a recording device such as a VTRand a monitor receiver for displaying a picture is utilized to preventduplication substantially.

[0007] In detail, a method in which a VTR performs AGC using a pseudosync signal inserted in an video signal and a monitor receiver employsAGC system not using the pseudo sync signal is an example of the formermethod, and in the method, an extraordinarily high level pseudo syncsignal is previously inserted as a sync signal for AGC when an analogvideo signal is recorded in an original recording medium, and then theextraordinarily high level pseudo sync signal is inserted in a videosignal supplied from a playback VTR to a recording VTR as a sync signalfor AGC.

[0008] A method utilizing the difference in APC characteristics in whichthe APC in a VTR follows a color burst signal in a video signal with ashort time constant but the APC in a monitor receiver follows with arelatively long time constant is an example of the latter method, and inthe method, the phase of a color burst signal of an video signal ispreviously inverted partially when analog video signals are recorded inan original recording medium, and then the video signal having thepartially inverted color burst signal is outputted as a video signalsupplied from a playback VTR to a recording VTR.

[0009] In the case described hereinabove, the monitor receiver whichreceives supply of the analog video signal from the playback VTRnormally plays back a picture without receiving an adverse effect of thepartial phase inversion of the color burst signal used for the pseudosync signal and APC.

[0010] However, in the VTR which receives supply of the analog videosignal having the inserted pseudo sync signal described hereinabovesupplied from the playback VTR or subjected to the phase inversioncontrol of the color burst signal and records the analog video signal ina recording medium, the VTR cannot perform gain control or phase controlbased on the input signal, and record the video signal not normally.Therefore, a normal picture cannot be viewed when the recorded videosignal is played back.

[0011] In the case which involves an analog video signal, theabove-mentioned methods do not involve duplication inhibition directly,but involves duplication of an abnormal video signal, namely passiveduplication prevention control.

[0012] On the other hand, in the case which involves a digitalinformation such as a video signal, an anti-duplication control signalsuch as an anti-duplication code or a duplication generation restrictioncode is added on a video signal as a digital data and it is recorded ina recording medium in order to inhibit the duplication, this method isregarded as direct duplication prevention control.

[0013] For example, FIG. 1 shows a basic structure of a recording devicewhich receives supply of a playback video signal obtained by playingback a recording medium where a video signal having an addedanti-duplication control signal is recorded as described hereinabove,and records (duplicates) the video signal in the recording medium 104.

[0014] In the case of this recording device, the recording devicereceives a playback video signal on which an anti-duplication controlsignal is added, and the playback video signal is supplied to a writesection 101 and anti-duplication control signal detection section 102.The anti-duplication control signal detection section 102 detects theanti-duplication control signal added on the playback video signal, andsupplies the detection result to a write control section 103 asduplication prevention control information.

[0015] The write control section 103 generates a control signal forcontrolling the write section 101 based on the supplied duplicationprevention control information, and supplies it to the write section101.

[0016] The write section 101 converts the playback video signal toinformation suitable for recording and writes it in a recording medium104 for performing recording if the control signal from the writecontrol section 103 permits duplication. On the other hand, the writesection 101 does not write the playback video signal in the recordingmedium 104 if the control signal from the write control section 103inhibits duplication.

[0017] Further, if the anti-duplication control signal detected by meansof the anti-duplication control signal detection section 102 permitsduplication of only first generation, then the write section 101converts the video signal to information suitable for recording andwrites it in the recording medium 104 for performing recording, and alsochanges the anti-duplication control signal added as additionalinformation to a duplication inhibition signal (duplication inhibitionof next generation), and records it in the recording medium 104. As theresult, the video signal cannot be duplicated using the duplicatedrecording medium 104.

[0018] As described hereinabove, in the case that an anti-duplicationcontrol signal is added on an information signal transmitted to arecording device, the duplication prevention control such as duplicationinhibition is performed consistently in a recording medium using such ananti-duplication control signal.

[0019] However, in the case of the recording device described using FIG.1, a significant lag time is required for detection processing of ananti-duplication control signal in the anti-duplication control signaldetection section 102 and for generation processing of a write controlsignal corresponding to anti-duplication control information in thewrite control section 103. Further, in the case that an anti-duplicationsignal is partially changed, more time is required.

[0020] From the above, some information signals are already recordedduring a time period from starting of duplication, followed by detectionof an anti-duplication control signal, to ending of execution ofduplication prevention control corresponding to the duplicationprevention control content which the detected anti-duplication controlsignal indicates, and as the result, some information signals arerecorded and remain in a recording medium though duplication of theinformation signal is inhibited.

[0021] In the case that it takes, for example, several seconds from thetime point of the starting of recording processing to the time pointwhen the duplication prevention control corresponding to ananti-duplication control signal added on an information signal becomesactive, it is possible to duplicate the entire information signal by wayof successive partial duplication of the information signal repeatedlyseveral seconds by several seconds though duplication of the informationsignal is inhibited.

[0022] A method in which a recording device is controlled so that theinformation signal is not recorded until the duplication preventioncontrol corresponding to an anti-duplication control signal added on theinformation signal to be duplicated becomes active is considered as aremedy.

[0023] However, in this case, the information signal is not recorded ina recording medium until the duplication prevention control content ofthe anti-duplication control signal added on the information signal isdetected to be duplication-permitted though duplication of theinformation signal is permitted. This method is disadvantageous in thatthe initial portion of the information signal is not recorded in arecording medium though duplication of the information signal ispermitted.

[0024] In view of the above-mentioned problems, the object of thepresent invention is to provide an information signal duplicationprevention method and an information signal duplication preventiondevice which are capable of perfectly preventing illegal duplication ofthe information signal.

SUMMARY OF THE INVENTION

[0025] An information signal recording control device for controllingthe recording of an information signal in a recording mediumcorrespondingly to the content of an anti-duplication control signaladded on an information signal, wherein the anti-duplication controlsignal added on the information signal is detected, the recording of theinformation signal in the recording medium is brought to a stop when thecontrol of the duplication prevention control of the detectedanti-duplication control signal is judged to be duplication-inhibited,and at least the information signal recorded by the time the recordingof the information signal in the recording medium is brought to a stopis erased from the recording medium.

[0026] Further in the present invention, the recording of theinformation signal is brought to a stop and the recording operation ismade impossible thereafter when the content of the duplicationprevention control of the anti-duplication control signal isduplication-inhibited.

[0027] To solve the above-mentioned problem, the information signalduplication prevention method described in claim 1 of the presentinvention comprises;

[0028] a step for detecting an anti-duplication control signal added onan information signal, and

[0029] a step for stopping duplication of the information signal and forerasing at least the information signal duplicated in a recording mediumby the time the duplication of the information signal is brought to astop when the duplication prevention control content of theanti-duplication control signal is detected to be duplication-inhibited.

[0030] The information signal duplication prevention method described inclaim 3 of the present invention comprises

[0031] a step for detecting an anti-duplication control signal added onan information signal, and

[0032] a step for stopping the duplication of the information signal andalso for making further duplication operation impossible when theduplication prevention control content of the anti-duplication controlsignal is detected to be duplication-inhibited.

[0033] According to the present invention, duplication of theinformation signal is brought to a stop and at least the informationsignal duplicated in a recording medium by the time the duplication ofthe information signal is brought to a stop is erased when theduplication prevention control content of the anti-duplication controlsignal added on the information signal to be duplicated is detected tobe duplication-inhibited.

[0034] In the case that the information signal is partially recorded ina recording medium though the information signal isduplication-inhibited because it takes a certain lag time before theduplication prevention control based on the anti-duplication controlsignal added on the information signal becomes active, and even thoughit is an information signal, when it is partially recorded in arecording medium, the information signal recorded on the recordingmedium is erased. Hence, recording of all the duplication-inhibitedinformation signal by duplicating repeatedly the partial informationsignals with successive shifting of the portion to be duplicated isprevented. As the result, the duplication of the information signal isprevented consistently and safely correspondingly to theanti-duplication control signal added on the information signal.

BRIEF DESCRIPTION OF THE DRAWINGS

[0035]FIG. 1 is a block diagram for illustrating one example of aconventional information signal duplication prevention device.

[0036]FIG. 2 is a block diagram for illustrating one embodiment of aninformation signal duplication prevention device in accordance with thepresent invention.

[0037]FIG. 3 is a block diagram for illustrating the erasing controlsection of the information signal duplication prevention device shown inFIG. 2.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0038] One embodiment of the information signal duplication preventionmethod and information signal duplication prevention device of thepresent invention will be described hereinafter with reference to thedrawings.

[0039] An information signal recording/playback device describedhereinafter is structured using the information signal duplicationprevention device of the present invention, the case that theinformation signal duplication prevention device is applied to a DVD(Digital Video Disk) recording/playback device (abbreviated simply asDVD device hereinafter) is described. For purpose of simplification,description of audio signal system is omitted.

[0040]FIG. 2 is a block diagram for illustrating the DVD device of thisembodiment. As shown in FIG. 2, the DVD device of this embodiment isprovided with an input terminal 1 for a video signal, an output terminal2 for a video signal, a recording/playback signal processing section 3,an anti-duplication control signal detection section 4, a systemcontroller 5 for controlling respective sections of this DVD device, aservo circuit 6, a recording/playback mechanical deck section 7 havingan optical pickup, a spindle motor, and a moving motor for moving theoptical pickup in the radial direction of a disk 100, a liquid crystaldisplay (LCD) 8, and a key operation section 9.

[0041] In FIG. 2, digitized video signals, audio signals, andanti-duplication prevention control signals as additional informationare recorded in the disk 100, and in this example, the disk 100 is aDVD.

[0042] In this embodiment, the anti-duplication control signal is asignal for indicating generation restriction such as duplicationpermission of the first generation, or duplication inhibition orpermission of the video signal, having one-bit or several-bit structure,added on the video signal.

[0043] The DVD device of this embodiment detects the anti-duplicationcontrol signal added on the video signal supplied through the inputterminal 1, and performs recording control of the video signalcorrespondingly to the duplication prevention control content of thedetected anti-duplication control signal when recording processing asdescribed hereinafter.

[0044] Recording processing in the DVD device of this embodiment isdescribed hereinafter.

[0045] The video signal S1 on which the anti-duplication control signalis added is inputted to the DVD device of this embodiment through theinput terminal 1. The input video signal S1 is supplied to therecording/playback signal processing section 3 and the anti-duplicationcontrol signal detection section 4.

[0046] The recording/playback signal processing section 3 is providedwith an RF circuit, generates a recording high frequency signal forrecording in the disk 100, and supplies it to the recording/playbackmechanical deck section 7. The recording/playback signal processingsection 3 receives supply of a signal corresponding to the reflectedlight from the disk 100 supplied from the recording/playback mechanicaldeck section 7, hence acquires information required for tracking servoand focus servo, and address information on the disk 100, and suppliesthis information to the system controller 5.

[0047] The system controller 5 generates a signal for controlling theservo circuit 6 based on the recording start indication information froma user inputted through the key operation section 9 and the informationrequired for servo control supplied from the recording/playback signalprocessing section 3 as described hereinabove, and supplies the signalto the servo circuit 6.

[0048] The servo circuit 6 generates a spindle servo signal, a trackingservo signal, a light power servo signal, and a focus servo signal, andsupplies these signal to the recording/playback mechanical deck section7.

[0049] The supply activates the recording/playback mechanical decksection 7 to start recording of a recording high frequency signalcorresponding to the input video signal S1 in the disk 100.

[0050] On the other hand, the anti-duplication control signal detectionsection 4 detects the anti-duplication control signal added on the videosignal S1 supplied to the section, and supplies the detectedanti-duplication control signal to the system controller 5 asanti-duplication control information S2.

[0051] In this embodiment, the system controller 5 functions as a writecontrol section, erasing control section, and recording inhibitioninformation memory section. Therefore, as shown in FIG. 2, the systemcontroller 5 is described as a system controller having a write controlsection 51, erasing control section 52, and recording inhibitioninformation memory section 53.

[0052] The write control section 51 continues duplication if theanti-duplication control information S2 permits duplication, on theother hand, generates a write control signal S3 for stopping duplicationand supplies it to the recording/playback signal processing section 3 ifthe anti-duplication control information inhibits duplication.

[0053] As the result, the recording/playback signal processing section 3supplies the recording high frequency signal in the disk 100 if thewrite control signal S3 indicates duplication continuation, on the otherhand, stops supply of the recording high frequency signal to prevent therecording high frequency signal from being written in the disk 100 ifthe write control signal S3 indicates duplication inhibition of thevideo signal S1.

[0054] As described hereinabove, the DVD device of this embodimentrecords the video signal even when the duplication prevention controlcorresponding to the anti-duplication control signal added on the videosignal S1 cannot be executed immediately because, for example, it takesa long time to detect the anti-duplication control signal in theanti-duplication control signal detection section 4.

[0055] By operating as described hereinabove, the disadvantage isavoided that the video signal is not recorded until the anti-duplicationcontrol signal is detected and the duplication prevention controlbecomes active though duplication of the video signal is permitted,which will happen in the case that the duplication prevention control isperformed so that the video signal is not recorded until the duplicationprevention control corresponding to the detected anti-duplicationprevention control signal added on the video signal becomes active asdescribed hereinbefore.

[0056] Further, the write control section 51 of the system controller 5of this embodiment generates a duplication control information includinginformation which indicates duplication prevention control contentindicated by the anti-duplication control information S2, a duplicationstart address, a duplication end address, a duplication date, and thetype of the signal to be duplicated, and information which indicatesduplication control content such as a copyright information of thesignal to be duplicated.

[0057] Herein, the duplication start address is an address on the disk100 at the starting time of duplication recording. The starting addressindicates the position on the disk 100 where recording of the recordinghigh frequency signal (video signal) acquired from the disk 100 andsupplied through the recording/playback signal processing section 3starts. The duplication end address indicates the position on the disk100 where duplication recording is brought to a stop. Therefore, theduplication address includes the address where the duplication isbrought to a stop forcedly because of duplication inhibition.

[0058] The duplication date is, for example, a date acquired from aclock circuit of the system controller 5 when a user inputs recordingstart indication information. The information which indicates the typeof signal to be recorded and the copyright information of the signal tobe recorded are signals acquired from the video signal S1.

[0059] The duplication prevention control content of theanti-duplication control signal can be uncertain because it takes a longtime to detect the anti-duplication control signal added on the videosignal S1 as described hereinbefore. In such a condition, theduplication prevention control content of the anti-duplication controlsignal is regarded as an uncertain condition.

[0060] Therefore, in this embodiment, the duplication controlinformation generated by the write control section 51 includesinformation for indicating duplication permission/uncertain/duplicationinhibition of the video signal S1 to be recorded, a duplication startaddress, a duplication end address, a duplication date, and duplicationcontent. In this embodiment, the duplication control information is usedby the erasing control section 52.

[0061]FIG. 3 is a block diagram for illustrating the erasing controlsection 52 of this embodiment. The erasing control section 52 isprovided with a duplication inhibition information detection section521, a recording information holding section 522, and a duplicationerasing control section 523 as shown in FIG. 3.

[0062] The duplication control information generated by the writecontrol section 51 is supplied to the duplication inhibition informationdetection section 521 and the recording information holding section 522of the erasing control section 52 .

[0063] The duplication inhibition information detection section 521detects whether duplication of the video signal S1 is inhibited, andsupplies the detection result to the duplication erasing control section523 and the recording information holding section 522.

[0064] The recording information holding section 522 is provided with atemporary memory region of information such as a RAM, extractsduplication history information such as the duplication start addressand the duplication end address, and duplication-related informationsuch as the duplication date and duplication content (information), andstores them temporarily.

[0065] The recording information holding section 522 supplies theduplication start address and the duplication end address whichindicates the recording position on the disk 100 of the video signalalready recorded in the disk 100 to the duplication erasing controlsection 523 immediately when the detection result obtained in theduplication inhibition information detection 521 is detected to beduplication-inhibited, and writes the duplication-related informationwhich is stored temporarily in the recording inhibition informationmemory section 53 to hold the duplication-related information as aduplication history.

[0066] The recording inhibition information memory section 53 isstructured using, for example, an EEPROM (Electrically ErasableProgrammable ROM), the duplication-related information is held after thepower source of the DVD device of this embodiment is shut down, and canbe erased when the recorded duplication-related information becomesunnecessary.

[0067] The duplication erasing control section 523 generates aduplication information erasing control signal for erasing the videosignal already recorded in the disk 100 during the recording processingof this time based on the duplication erasing information supplied fromthe recording information holding section 522 if the detection resultobtained in the duplication inhibition information detection section 521indicates duplication inhibition.

[0068] In this embodiment, the video signal recorded in the memoryregion ranging from the duplication start position indicated by theduplication start address to the duplication end position on the disk100 in which the video signal is recorded during the recordingprocessing of this time is erased.

[0069] Further, for example, in the case that the video signal isrecorded on separated regions in the disk 100 as the result of recordingselectively on free regions in the disk 100, all the video signalsrecorded on the separated regions this time are erased.

[0070] Thereby, only the video signal which has been recorded in thedisk 100 is erased by the time the duplication prevention controlcontent indicated by the anti-duplication control signal is detected tobe duplication-inhibited without erasing video signals which wasrecorded legally prior to this recording processing.

[0071] The system controller 5 generates a signal for controlling theservo circuit 6 correspondingly to the duplication information erasingcontrol signal generated by the duplication erasing control section 523,and supplies it to the servo circuit 6. The servo circuit 6 generatesvarious servo control signals as described hereinbefore correspondinglyto the signal supplied from the system controller 5, and supplies themto the recording/playback mechanical deck 7.

[0072] The respective components of the recording/playback mechanicaldeck section 7 operate so as to erase the video signal recorded on theregion where the video signal is actually recorded by this recordingprocessing.

[0073] By operating as described hereinabove, the video signal recordedin the disk 100 by the time the duplication prevention controlcorresponding to the anti-duplication control signal becomes activethough the duplication prevention control content of theanti-duplication control signal added on the video signal indicatesduplication inhibition is erased from the disk 100.

[0074] Further, when the erasing of the video signal recorded in thedisk 100 before the duplication prevention control corresponding to theanti-duplication control signal becomes active is completed, then theduplication-related information written in the recording inhibitioninformation memory section 53 is erased.

[0075] However, even in the case that the video signal is recorded inthe disk 100 though duplication is inhibited, and the power source ofthe DVD device of this embodiment is shut down before the video signalduplicated in the disk 100 is erased, the duplication-relatedinformation written in the recording inhibition information memorysection 53 is not erased.

[0076] Hence, because the duplication-related information is stored inthe recording inhibition information memory section 53, by erasing thevideo signal recorded in the disk 100 using the duplication-relatedinformation when the power source of the DVD device is supplied again,the video signal, which is originally a duplication-inhibited videosignal, recorded in the disk 100 is erased consistently by the time theduplication prevention control corresponding to the anti-duplicationcontrol signal becomes active.

[0077] The duplication-inhibited video signal does not remain evenpartially in the disk 100 as described hereinabove, and the duplicationprevention control corresponding to the anti-duplication control signaladded on the video signal is performed consistently.

[0078] Therefore, as described hereinbefore, it is impossible toduplicate all the duplication-inhibited video signal by repeatingpartial recording with successive shifting of a portion of the videosignal to be recorded utilizing the lag time recording that theduplication-inhibited video signal is recorded by the time theduplication prevention control corresponding to the anti-duplicationcontrol signal becomes active because it takes a long time to detect theanti-duplication control signal added on the video signal.

[0079] In the case that the duplication prevention control correspondingto the anti-duplication control signal added on the video signal isperformed and the video signal to be duplicated is aduplication-inhibited video signal, the DVD device of this embodimentdisplays a message for indicating that the video signal to be duplicatedis duplication-inhibited on the LCD 8 after completion of erasing of thevideo signal recorded in the disk 100 before starting of the duplicationprevention control corresponding to the anti-duplication control signalunder the control of the system controller 5.

[0080] In this case, the DVD device of this embodiment continues todisplay a message for indicating recording condition until completion oferasing of the video signal recorded on the disk 100 recorded by thetime the duplication prevention control corresponding to theanti-duplication control signal becomes active.

[0081] By operating as described hereinabove, a user does not recognizethat the duplication-inhibited video signal recorded in the disk 100 iserased by the time the duplication prevention control corresponding tothe anti-duplication control signal becomes active.

[0082] To erase the duplication-inhibited video signal recorded in thedisk 100 by the time the duplication prevention control corresponding tothe anti-duplication control signal becomes active, the video signalrecorded in the disk 100 may be erased physically or may be erasedlogically by re-writing information of a directory for managing therecording region of the disk 100. Anyway, the important thing is thatthe information is not read out from the disk 100.

FIRST MODIFIED EXAMPLE

[0083] In the DVD device described using FIGS. 2 and 3, in the case thatthe detection result in the duplication inhibition information detectionsection 521 is duplication inhibition, all the information recorded onthe region where the video signal is actually recorded this timefollowing the recording start position indicated by the duplicationstart address on the disk 100 on which the video signal is recorded thistime. Therefore video signals which were recorded legally in the disk100 before recording this time remain.

[0084] On the other hand, in this first modified example, in the casethat the detection result in the duplication inhibition informationdetection section 521 is duplication inhibition, for example, all thevideo signals recorded in the disk 100 are erased to penalize a user whointended to duplicate illegally the duplication-inhibited video signal.

[0085] In the case that all the video signal recorded in the disk 100 iserased, the duplication-inhibited video signal is erased consistently.Because all the video signals including video signals which wererecorded legally before recording this time are erased in this case, auser tends not to duplicate illegally so as to avoid erasing of legallyduplicated video signals.

[0086] Further in the case that all the video signals recorded in thedisk 100 are erased, it is unnecessary for the duplication-relatedinformation temporarily stored in the recording information holdingsection 522 and the duplication-related information written in therecording inhibition information memory section 53 to include theduplication start address and duplication end address.

SECOND MODIFIED EXAMPLE

[0087] The DVD device described with reference to FIGS. 2 and 3 is adevice for duplicating the video signal supplied through the inputterminal 1, however the video signal is not limited to a video signalsupplied from the same recording medium.

[0088] For example, in the case of edit processing in which a pluralityof different video signals are compiled, it is considered, for example,that a duplication-permitted video signal and a differentduplication-inhibited video signal are supplied alternately to the DVDdevice shown in FIG. 2 with switching using a switcher to recordcombined video signals in the disk 100.

[0089] In such case, it is possible that the duplication preventioncontrol content of the anti-duplication control signal changes duringone recording processing. For example, the duplication preventioncontrol content of the anti-duplication control signal is a mixture of aduplication-permitted condition, an uncertain condition in which thecondition is neither duplication-permitted nor duplication inhibited,and a duplication-inhibited condition.

[0090] Herein, the uncertain condition is a condition under detectionprocessing of the anti-duplication control signal, or a condition inwhich it is not clear which of duplication-permission andduplication-inhibition is detected because the duplication preventioncontrol corresponding to the anti-duplication control signal is underdetection processing.

[0091] In the case that the duplication prevention control content ofthe anti-duplication control signal changes during one recordingprocessing, it is desirable to perform the duplication preventioncontrol corresponding to the current duplication prevention control.However, because the uncertain condition of the content of theduplication prevention control occurs, it is possible that the videosignal cannot be recorded through it is actually a video signal on whichthe anti-duplication control signal for indicating duplicationpermission is added, or that the video signal is recorded though it is avideo signal on which the anti-duplication control signal for indicatinginhibition is added.

[0092] The duplication-related information including the duplicationstart address, the duplication end address, the duplication date, theduplication content (information), and the number of times of detectionof duplication inhibition generated from the recording inhibitioninformation holding section 522 is held temporarily together with thedetection information of the duplication prevention control (referred toas detection information hereinafter) that is information for indicatingany of duplication permission/uncertain/duplication inhibition used asinformation for indicating the duplication prevention control contentdetected based on the anti-duplication control signal, and the detectioninformation is added also to the duplication-related information to bewritten in the recording inhibition information holding section 53.

[0093] The video signal from which the duplication prevention controldetection result of the duplication permission or uncertain condition isrecorded in the disk 100.

[0094] When the detection of the duplication prevention control contentis changed from the uncertain condition to duplication inhibition in theduplication inhibition information detection section 521, the videosignal of the portion where the duplication prevention control contentis uncertain and the portion where the duplication prevention controlcontent is duplication-inhibited recorded on the disk 100 is erased bythe time the duplication prevention content of the anti-duplicationcontrol signal is detected to be duplication-inhibited, except for theduplication-permitted portion based on the duplication-relatedinformation having the detection information added thereon whichindicates the uncertain condition and the duplication-relatedinformation having the detection information added thereon whichindicates duplication inhibition.

[0095] When the duplication prevention content is changed from theuncertain condition to duplication permission in the duplicationinhibition information detection section 521, the video signal recordedin the disk 100 is not erased.

[0096] Hence, even when the duplication prevention control content ofthe anti-duplication control signal added on the video signals changed,the duplication prevention control corresponding to the anti-duplicationcontrol signal is performed as described hereinbefore.

THIRD MODIFIED EXAMPLE

[0097] In the DVD device described with reference to FIGS. 2 and 3, theduplication-inhibited video signal is prevented from being illegallyduplicated by stopping the recording and erasing the video signalrecorded in the disk 100 when the duplication prevention control contentof the anti-duplication control signal added on the video signal isdetected to be duplication-inhibited.

[0098] However, such a duplication prevention control method is notsufficient to sweep off the illegal duplication itself of the videosignal by identifying and prosecuting offenders who are involved inillegal duplication of video signals and involved in dealing of suchdisks manufactured illegally.

[0099] To make the duplication prevention control effective, the systemcontroller 5 of the DVD device is made incapable of recording when theduplication prevention control content is detected to beduplication-inhibited in the duplication inhibition informationdetection section 521.

[0100] By structuring as described hereinabove, recording processingcannot be performed using this DVD device thereafter, and the offenderwho intended illegal duplication is defeated.

[0101] In the case of this DVD device, because the device also has aplayback function, not only the recording processing is made impossible,but also all the functions of this DVD device including playbackprocessing are made impossible when the duplication prevention controlcontent is detected to be duplication-inhibited.

[0102] In the case that the recording processing is made impossiblethereafter when the duplication prevention control content is detectedto be duplication-inhibited as described hereinabove, because it isimpossible to duplicate all the duplication-inhibited video signals byrepeating partial duplications of the video signal with shiftingsuccessively of the portion to be duplicated, it is an option not toerase the video signal recorded in the disk 100 by the time theduplication is brought to a stop.

FOURTH MODIFIED EXAMPLE

[0103] The case that the DVD device is made incapable of performingrecording processing thereafter when the duplication prevention controlcontent is detected to be duplication-inhibited as described in thethird modified example is, in some cases, too severe for general users.

[0104] To mitigate the severity, every time the duplication informationholding section 522 is informed of detection of duplication inhibitionby the duplication inhibition information detection section 521, and theduplication information holding section 522 adds the number of times ofdetection of duplication inhibition and acquires and holds the number oftimes of detection of duplication inhibition of the duplicationprevention control content of the anti-duplication control signal.

[0105] The number of times of duplication inhibition detection is storedin the duplication information holding section 522 and in the recordinginhibition information memory section 53 as a part of theduplication-related information, and every time when a duplicationinhibition is detected, whether the number of times of duplicationinhibition detection exceeds a pre-determined restriction number isjudged.

[0106] When the number of times of duplication inhibition detectionexceeds the pre-determined restriction number, the system controller 5judges that the duplication-inhibited video signal is about to beillegally duplicated intentionally using this DVD, and then the DVDdevice is made incapable thereafter of performing recording processing.

[0107] In this case, if a user inputs recording start indication, thesystem controller 5 does not accept this indication, and the followingrecording processing is made impossible to be performed.

[0108] By structuring as described hereinabove, if the video signalhaving the added anti-duplication control signal which indicatesduplication inhibition is set to be duplicated only once by mistake,only this duplication-inhibited video signal is made impossible to beduplicated, and thereafter recording processing of aduplication-permitted video signal or recording processing of a videosignal taken by the user itself using a video camera can be performednormally. Therefore this case is not so severe for users.

[0109] A parameter of duplication date of the duplication-relatedinformation is involved in addition to the number of times ofduplication inhibition detection, recording processing may be madeimpossible thereafter when the number of times of duplication inhibitiondetection exceeds a limited number within a pre-determined time period.

[0110] As described hereinabove, in the case that theduplication-inhibited video signal is intended to be duplicatedrepeatedly in the DVD device of this embodiment, the DVD device itselfis made incapable of performing recording processing, thereby the actionitself to duplicate illegally the duplication-inhibited video signal isprevented.

[0111] When the number of times of duplication inhibition detectionexceeds a limited number, not only the recording processing, but alsothe playback processing, namely all the functions of this DVD device,may be made impossible to use.

[0112] In the case that the recording processing is made impossiblethereafter when the number of times of duplication inhibition detectionexceeds the limited number, because it is impossible to duplicate allthe duplication-inhibited video signals by repeating partialduplications with successive shifting of the portion to be duplicatedlike the abovementioned third modified example, it is an option not toerase the video signal recorded by the time the duplication is broughtto a stop.

FIFTH MODIFIED EXAMPLE

[0113] In the DVD device described with reference to FIGS. 2 and 3, inthe case that the duplication prevention control con-tent is detected tobe duplication-inhibited, recording processing is brought to a stop andalso the video signal recorded in the disk 100 is erased, theduplication-related information (duplication history) written in therecording inhibition information memory section 53 is erased whenerasing of the video signal, which is recorded in the disk 100 by thetime the duplication prevention control content is detected to beduplication-inhibited and the recording processing is brought to a stop,is completed normally.

[0114] When erasing the video signal, which is recorded in the disk 100before the duplication prevention control corresponding to theanti-duplication control signal becomes active, is completed normally,the duplication-related information held in the recording informationmemory section 53 is also erased, therefore, if the duplicationprevention control corresponding to the anti-duplication control signaladded on the video signal is performed, the information which indicatesthe duplication prevention control is erased.

[0115] In other words, in the case that recording processing is broughtto a stop and the video signal recorded in the disk 100 is erasedbecause the anti-duplication control signal to inhibit duplication wasadded on the video signal intended to be duplicated, the case cannot bedistinguished from the case that the video signal cannot be duplicateddue to failure of this DVD.

[0116] In such a case, it is required to check the failure of the DVDdevice or to check whether the anti-duplication control signal forduplication inhibition is added on the video signal which could not beduplicated, and such checking takes extra work and time. Hence, itoccurs that complains from users that the DVD cannot record while it isa DVD device having recording function are not responded quickly.

[0117] To cope with the problem, when erasing of the video signalrecorded in the disk 100 is completed as mentioned above by the time theduplication prevention control corresponding to the anti-duplicationcontrol signal becomes active, the duplication-related information isnot erased from the recording inhibition information memory section 53,but information (referred to as erasing completion informationhereinafter) which indicates completion of erasing of the video signalrecorded in the disk 100 is added to the duplication-relatedinformation, and the added duplication-related information is written inthe recording inhibition information memory section 53 to store theduplication-related information in the recording inhibition informationmemory section 53.

[0118] By keeping the duplication-related information in the recordinginhibition information memory section 53, when the video signal cannotbe duplicated, it is clearly identified whether the trouble is due toduplication control because of the duplication-inhibited video signal ordue to failure or mis-operation of the DVD device. By performing asdescribed hereinabove, it is possible to respond quickly, correctly, andeasily to users' complains that the DVD does not function to record thevideo signal.

[0119] Whether erasing of the video signal, which is recorded in thedisk 100 is completed by the time the duplication prevention controlcontent of the anti-duplication control signal is detected to beduplication-inhibited and the recording processing is brought to a stop,is judged based on the existence of the erasing completion informationas described hereinabove.

[0120] Hence, as described hereinabove, even if the power source of theDVD device is shut down before or during erasing of the video signalrecorded in the disk 100, when the power source is supplied again in thecase that there is no erasing completion information in the recordinginhibition information memory section 53, the duplication-inhibitedvideo signal is prevented perfectly from being duplicated by performinganother processing for erasing the video signal recorded in the disk100. Thus, it is possible to prevent duplication of all theduplication-inhibited video signals by repeating partial duplication.

[0121] The remaining duplication-related information in the recordinginhibition information memory section 53 can serve to judge whether thisDVD device is a DVD device which has tried to duplicate the video signalillegally. As described hereinabove, the duplication-related informationcan be used as the information to prosecute offenders who intended toduplicate illegally using this DVD, and is very effective to preventillegal duplication itself of the video signal.

[0122] In the above-mentioned embodiment, the information which is thecomponent of the duplication-related information held in the recordinginformation holding section 522 and recording inhibition informationmemory section 53 is not limited to the above-mentioned information.

[0123] Various information which is obtained and required for the DVDdevice of the embodiment, for example, information regarding thesupplier of the video signal such as the type of the recording medium inwhich the video signal to be duplicated is recorded or copyrightinformation, may be written in the recording inhibition informationmemory section 53.

[0124] In the above-mentioned embodiment, the DVD device to which thepresent invention is applied is described, however the present inventionis not limited to the DVD device, and the present invention may beapplied to recording device and recording/playback device such as a VD(Video Disk), an HD (Hard Disk), an FD (Floppy Disk), and an MD (a smallmagneto-optical disk called as Mini Disk).

[0125] Of course, the present invention can be applied to a VTR (VideoTape Recorder) and a cassette tape recorder. To apply the presentinvention to a VTR and a cassette tape recorder, a tape counter value atthe starting of a recording, a tape counter value at the end of arecording may be used or a time record recorded in a magnetic tape maybe used instead of the duplication start address and the duplication endaddress held as the duplication-related information.

[0126] The information signal to be duplicated in a recording mediumsuch as a disk or a magnetic tape is not limited to a video signal, andvarious information signals such as an audio signal and text data may beused. The present invention is applied in all the cases that thesevarious information signals are duplicated.

[0127] The information signal is not limited to a digital signal, andthe present invention is also applied to an analog information signal.

[0128] The anti-duplication control signal may be a signal which can beadded on an information signal such as a video signal and may besupplied together with the information video signal to a recordingdevice for recording the information signal such as a DVD device, andvarious types of anti-duplication control signals may be used.

[0129] For example, an anti-duplication control signal is spectrallyspread using a PN (Pseudorandom Noise) series code as a spread code, thespectrally spread anti-duplication control signal is superimposed on aninformation signal, and the superimposed information signal may besupplied to a recording device for recording.

[0130] In this case, the anti-duplication control signal detectionsection 4 is provided with a PN code generator which generates the samePN code as the one used for the spectral spread and a multiplyingcircuit, and the original anti-duplication control signal may beextracted by performing spectral inversion spread.

[0131] In the above-mentioned embodiment, the case that the video signalto be duplicated on which the anti-duplication control signal is addedis supplied through the input terminal 1 in FIG. 2 is described, howevera supply source of the information signal, a video signal in this case,may be various playback devices for playing back the information signalor may be reception devices for receiving the transmitted informationsignal.

[0132] In the case of a recording/playback device for performingplayback processing and recording processing simultaneously, the presentinvention is applied to the case that an information signal played backin the playback device section of the recording/playback device isrecorded in the recording device section of the recording/playbackdevice.

[0133] In the case of such a recording/playback device capable ofperforming playback processing and recording processing simultaneously,it is not required that an anti-duplication control signal added on aninformation signal is supplied to the recording device section.

[0134] In the case of such a recording/playback device in which therecording medium of an information signal to be played back is, forexample, a disk, the present invention is applied to the case that ananti-duplication control signal recorded on TOC (Table Of Contents) ofthe disk of the playback side read out in the playback device section oron track area called directory is detected, and the duplicationprevention control corresponding to the detected anti-duplicationcontrol signal is performed.

[0135] As described hereinbefore, according to the information signalduplication prevention method and information signal duplicationprevention device in accordance with the present invention, therecording processing is controlled correspondingly to theanti-duplication control signal added on the video signal to beduplicated. If the anti-duplication control signal indicates duplicationinhibition, the recording processing is brought to a stop, and theinformation signal recorded in the recording medium is erased by thetime the recording processing is brought to a stop. Thereby theduplication of the duplication-inhibited information signal is preventedperfectly from being duplicated.

What is claimed is:
 1. An information signal recording control methodfor controlling recording of an information signal in a recording mediumcorrespondingly to the content of an anti-duplication control signaladded on an information signal comprising: a step for detecting saidanti-duplication control signal added on said information signal; a stepfor stopping said recording of said information signal in said recordingmedium when said content of the duplication prevention control of saiddetected anti-duplication control signal is judged to beduplication-inhibited; and a step for erasing from said recording mediumat least said information signal recorded by the time said recording ofsaid information signal in said recording medium is brought to a stop.2. The information signal recording control method as claimed in claim 1, wherein a recording region information including the starting pointand the ending point of said recording on said recording medium wheresaid information signal is recorded is stored, and said recordedinformation signal is erased based on said recording region information.3. The information signal recording control method as claimed in claim 1, wherein all the information in said recording medium is erased whensaid recording of said information signal in said recording medium isbrought to a stop.
 4. An information signal recording control method forcontrolling recording of an information signal in a recording mediumcorrespondingly to the content of an anti-duplication control signaladded on an information signal comprising: a step for detecting saidanti-duplication control signal added on said information signal; a stepfor stopping said recording of said information signal in said recordingmedium when said content of the duplication prevention control of saiddetected anti-duplication control signal is judged to beduplication-inhibited; and a step for making said recording operation ofsaid information signal impossible thereafter.
 5. The information signalrecording control method as claimed in claim 4 , wherein the number ofduplication-inhibited judgments of said content of said detectedanti-duplication control signal is counted, and said recording operationof said information signal is made impossible thereafter when saidnumber of judgment reaches a prescribed number.
 6. An information signalrecording control device for controlling recording of an informationsignal in a recording medium correspondingly to the content of ananti-duplication control signal added on an information signal providedwith: an anti-duplication control signal detection means for detectingsaid anti-duplication control signal added on said information signal; arecording control means for stopping said recording of said informationsignal in said recording medium when said content of the duplicationprevention control of said detected anti-duplication control signal isjudged to be duplication-inhibited, and an erasing means for erasingfrom said recording medium at least said information signal recorded bythe time said recording of said information signal in said recordingmedium is brought to a stop.
 7. The information signal recording controldevice as claimed in claim 6 , wherein a memory means for storing arecording region information including the starting point and the endingpoint of said recording in said recording medium where said informationsignal is recorded is provided, and recorded said information signal iserased based on said recording region information.
 8. The informationsignal recording control device as claimed in claim 7 , wherein saiderasing control means erases all the information in said recordingmedium when said recording of said information signal in said recordingmedium is brought to a stop.
 9. An information signal recording controldevice for controlling recording of an information signal in a recordingmedium correspondingly to the content of an anti-duplication controlsignal added on an information signal provided with: an anti-duplicationcontrol signal detection means for detecting said anti-duplicationcontrol signal added on said information signal; a recording controlmeans for stopping said recording of said information signal in saidrecording medium when said content of the duplication prevention controlof said detected anti-duplication control signal is judged to beduplication-inhibited; and a control means for making said recordingoperation impossible thereafter.
 10. The information signal recordingcontrol device as claimed in claim 9 , wherein the number ofduplication-inhibited judgments of said content of said detectedanti-duplication control signal is counted, and said recording operationof said information signal is made impossible thereafter when saidnumber of judgment reaches a prescribed number.
 11. An informationsignal recording control device for controlling recording of aninformation signal in a recording medium correspondingly to the contentof an anti-duplication control signal added on an information signalprovided with: a recording signal processing means for receiving supplyof an information signal and generating an recording information signal;a recording and erasing means capable of recording said recordinginformation signal supplied from said recording signal processing meansin a recording medium, and of erasing said recording information signalrecorded in said recording medium; an anti-duplication control signaldetection means for detecting said anti-duplication control signal addedon said information signal; a recording control means for controllingsaid recording signal processing means so as to stop supply of saidrecording information signal to said recording medium when said contentof said duplication prevention control of detected said anti-duplicationcontrol signal is judged to be duplication-inhibited; and an erasingcontrol means for controlling said recording and erasing means so as toerase from said recording medium said information signal recorded by thetime recording of said information signal on said recording medium isbrought to a stop based on said content of said anti-duplication controlsignal.
 12. The information signal recording control device as claimedin claim 11 , wherein a memory means for storing a recording regioninformation including the starting point and the ending point of saidrecording on said recording medium where said information signal isrecorded is provided, and recorded said information signal is erasedbased on said recording region information.
 13. The information signalrecording control device as claimed in claim 12 , wherein said recordingmedium is a disk-type recording medium, and said starting point andending point of said recording are indicated with the address in saiddisk-type recording medium.
 14. The information signal recording controldevice as claimed in claim 12 , wherein said recording medium is atape-type recording medium, and said starting point and ending point ofsaid recording are indicated with the value of a tape counter providedon said recording and erasing means.